refactor: bind embargo.api.check_course_access at call time

Running `pytest openedx/core/djangoapps/embargo/tests/` in isolation
fails one test because `test_redirect_if_blocked_courseware` mocks
`embargo.api.check_course_access`, and the mocked call triggers the
first-time import of `embargo.views`. views.py's `from .api import
check_course_access` captures the MagicMock as
`views.check_course_access` permanently. CI doesn't hit this because
earlier shard directories preload `embargo.views` before any mock
fires. Reproduces on master.

Calling via the module attribute resolves at call time, so future
mocks on the api function stay visible to the view.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: feanil

openedx/core/djangoapps/embargo/views.py

@@ -13,8 +13,7 @@
 
 from common.djangoapps.edxmako.shortcuts import render_to_response
 
-from . import messages
-from .api import check_course_access
+from . import api, messages
 
 
 class CheckCourseAccessView(APIView):  # pylint: disable=missing-class-docstring
@@ -48,7 +47,7 @@ def get(self, request):
                     course_key = CourseKey.from_string(course_id)
                 except InvalidKeyError as exc:
                     raise ValidationError('Invalid course_ids') from exc
-                if not check_course_access(course_key, user=user, ip_addresses=[user_ip_address]):
+                if not api.check_course_access(course_key, user=user, ip_addresses=[user_ip_address]):
                     response['access'] = False
                     break
         else: